Time magazine’s “Person of the Century,” Albert Einstein was a
founding member of the Princeton Federation of Teachers Local 552
union, signing its charter in 1938.

In colonial, times, carpenters, cabinetmakers, and cobblers'
guilds worked to improve pay. In 1825, Boston carpenters struck for the
10-hour workday. In 1886, 5,000 members of the Knights of Labor
conducted the first major strike, against the Iron Mountain Railroad in
Arkansas.